Fainting is when you lose consciousness for a short time because your brain is not getting enough oxygen. The medical term for fainting is syncope, but it is commonly known as "passing out." A fainting spell generally lasts from a few seconds to a...

An abnormal heart rhythm (arrhythmia) is a change in the heart's beating pattern. There are many different types with different causes and effects. Possible symptoms are feeling faint, chest pain, and sweating.

The heart rate, usually measured by checking the arterial pulse or sounds counting the times of the heart beat, is considered one of the vital signs. Vital signs – body temperature, pulse, breathing rate, and blood pressure provide information about the state of health of a person and, if abnormal, offer clues to problems.

The heart rate, usually measured by checking the arterial pulse or sounds counting the times of the heart beat, is considered one of the vital signs. Vital signs – body temperature, pulse, breathing rate, and blood pressure provide information about the state of health of a person and, if abnormal,offer clues to problems.

Fatigue is a term used to to describe the general overall feeling of tiredness and/or a lack of energy. Other words that are sometimes used in place of fatigue include exhaustion, weariness, and lethargy. According to the National Institutes of He...